Load-carrying and launching device



Oct. 13, 1931. A. D. M KENZIE LOAD CARRYING AND LAUNCHING DEVICE Filed Jan. 20, 1930 4 Sheets-Sheet l bwww Oct. 13, 1931. A. D. McKE z 1,827,534

LOAD CARRYING AND LAUNCHING DEVICE Filed Jan. 20, 1930 4 Sheets-Sheet 2 Arm NE).

Oct. 13, 1931. MCKENZIE 1,827,534

LOAD CARRYING AND LAUNCHING DEVICE Filed Jan. 20, 1930 4 Sheets-Sheet 3 I. g 44 Z //V&/EN779E:

5 7 Axvaus ,0 M A Hvz/E 4 Sheets-Sheet 4 A. D. M KENZIE LOAD CARRYING AND LAUNCHING DEVICE Filed Jan. 20, 1930 Oct. 13, 1931.

Patented Oct. 13, 1931 UNITEDISVTATES PATENT oFFicE.

AFCTGUS D. MCKENZIE, OF MANSFIELD, OHIO, ASSIGNOR TO THE AMERICAN SAFETY NAVIGATION COMPANY, OF CANTON, OHIO, A CORPORATION OF OHIO LOAD-CARRYING AND LAUNCHING DEVICE 7 Application filed January 20, 1930. Serial No. 421,920.

7 My invention relates to davits' for life boats and particularly to devices of this character which are gravity operated, and are high slung so as to "take up a minimum of deck space. The objects of the invention are to design such apparatus which may be easily operated, which is simple-in its mechanical make-up, and which offers the least p0ssibility of being jammed and rendered inopera- 1o tive.- i

The annexed drawings and the following description set forth in detail certain means embodying my invention, such disclosed means constituting, however, but two of the various forms in which the principle of the invention may be embodied. I

In said annexed drawings: Figure 1 is aside elevation of my improved davit construction,showing the same supporting a life boat, the upright or stationary supporting position of the davit being shown in full lines and a launching position being shown in broken lines; r

V Figure 2 is abroken side elevation of conventional control mechanism adapted to be utilized with my invention;

. Figure 3 is an end elevation of the drums and associated gearing shown in Figure 2;

' Figure 4 is a broken'front elevation of the parts shown in full lines in Figure 1;

Figure 5 is a fragmentary vertical section, upon an enlarged scale, taken in the plane indicated by the line 55, Figure 1;

Figure 6 is a fragmentary plan section, 5 upon an enlargedscale, taken in the planes indicated by the line 66, Figure 1; Figure 7 is a side elevation of a modified type of davit construction in uprightstationary supporting position; in Figure 8 is a fragmentary plan view of the elements shown in Figure 7 and V Figure 9 is a front elevation of the constructionshown in Figure 7,

7 Referring tothe annexed drawings in which the samepartsare indicated by the same respective numbers in the several views, 1 my improved davit construction "consists of three main parts, viz.,' a boom member, a support for carrying the life boat or other load when the latter is in its normal position,

and a cable for raising and lowering the boat. The launching of the load is effected completely by gravity, but controlled by mechanism designed properly to regulate the launching speed. c

Referring particularly to Figures 1 to 6, inclusive, in which the invention is illustrated by its application in boat-launching mechanism, upon the ship deck 1 I provide a suitable main support, the latter, for purposes of illustration in the accompanying drawings, being shown as the frame 2 of. a deck house, for instance. This main support 2 is located a suitable distance within the ship rail 3 over which the boat 19 must be launched when it is desired to lower the same into the water. Upon a pivot pin 5 mounted in the main support 2 adjacent the deck 1 I support a boom member 4 which, as will be plainly seen in Figure 1, is in normal load-carrying position a substantially vertically-.clisposed member for the greater part of its length, being sharply curved outwardly at the top toward the rail 3 of the ship, so as to permit the vertical dependency of the life boat 19 from the upper end of the boom member 4, the inner side of the boat 19 lying under the upper curved end of the boom, as will be readily seen and understood. Secured by a pivot pin 7 to the main support 2 in the form of device illustrated, is a depending link 8, the lower end of which is adapted to engage a pin 9 upon which is rotatably mounted a roller 11, the link 8 being formed with an elongated recess 10 by means of which the pin 9 may move lengthwise of the link 8, the roller 11 during this lengthwise movement riding upon a track member 12 secured to the face of the main support 2. This pin 9 and roller 11 are carried by one end of a support for carrying the life boat in its elevated normal. position, this support being in the form of a bell crank comprised of the two portions 14 and 15 pivoted at their angle point upon a pin 13 se cured in the boom 4, the leg 14 being pivotally connected. to the link 8 by means of the pin 9 which is fixedly mounted in the'end of leg 14 ,and the leg 15 contacting the life boat through the medium of sh es 16. 17 and 18 which abut the life boat 19, when the latter is in its normal raised position, as plainly shown in'Figure 1, whereby to steadily and adequately support the life boat.

To any suitable frame member of the life boat 19, such as a seat or block 20 secured substantially midway the width and as high as is practicable and near the end of the boat 19, is attached one end of a cable section 21 by any approved form of book 60, a block 36 being secured to the other end of said cable section 21. by means of a .pin 22. Pin

secured adjacent the upper end of this block 36 abuts the surface 37 of the topportion of the boom 4. v Secured topin 35 in one end of a cable 24 which plays over a'pair of pulleys 23 and 25 mounted onthe boom '4, said cable 24 also playing overa' sheave or cable guiding means 26 mounted uponthe main support2 whence the cable 24 passes to-a suitable control mechanism 52, Figures 2. and 3, consist-' ing of hoisting apparatusadapted tolower and lift the boat 19, at the desired speed. This control mechanism 52 is common to two launching devices such as has been described,

- one'for each end. of the boat 19, the control mechanismbeing adapted to take inor play 'out'the cables 24 in equal amounts. 1

I No claim is made to any invention in the control mechanism, ,one conventional [form of which is shown in Figures 2, and 3, which includes a motor 53' tOWllOSGlSlltft is fixed a pinion 54 engaginga. spurgear 56 secured ,to

one end of shaft 57, and pinion 58, being secured to the oppositeendof said shaft and engaging a pair ofgears .55secured respectively toza pair. of shafts to which are secured drums 59 upon which thecables24 are adapted to be wound. Suitable mechanism is thus provided for the desired gear reductions,

the paying-out and drawing-in of the cables 24, and other actions necessary in such mechanism.

' curedto the main support 2 and thus. prevent the further outward movement ofthe boom.

"In order that the boom may not move inwardly, when in this locked position, I pro"- vide a'clamp ngbolt 33 ntersect ng a block 34 V mounted between-two of the upright angles 30, which bolt 33 canbe turned tightly up against the inner face of the-boom4 and thus hbldthe shoulder member 39-and the looking dog 32 closely in engagement.

The function of the. counterwelght 29 'to up, so that, during the hoisting operation,this' The load on the cable 24 plus the weight of the boom 4 and the boat support 14-15, is more thansuflicient to rotate the latch 28, on the pin 27, and to release shoulder 39 from dog 32 during the launching operation, when the latch 31 is pulled off the end of said latch 28 sd-as to'release the latter."

been described only one of a pair of duplicate parts forming my entire davit construction, there beinglprovided one ofthese parts for supporting and operating each end of the boat .19, as suggested in Figure .4, both of these sets of operating elements being controlled .through'one main hoisting and control apparatus 52 which operatesthe pair of cables 24.1: r

In the formof'device shown in Figures 7, 8, and 9, only one boom structure isutilized, the same beinga centrally'located device, relative to the boat 41, but constructed and op erated substantially-along the lines of the device shown in Figures 1, 4, 5 and 6,the

' changes requiredbeing that of widening out the boat support so as to give a suflieient bear ingforthe life boat, and in providing a spreader at the top end'of the ,boom upon which pulleys maybe mounted. overv which the two cables-run, which support the two ends oftheboat. Such asingle davit construction can be seen in Figure 9 wherein the boat 41 is supported by two cables 42 a Y tached mine boat members 20' which cables 42play over "pulleys hung from the ends of a spreaderinember 43 mounted adjacent the top ofthe'boom-whence the cables 42 pass to-and over a pairof pulleys 49 and .50 supported respectively upon the spreader 43 and upon theupright portions of the boom adjacent the top of the latter, whence the cables pass tot-he sheaves126 and to the common control mechanism 52. In this form of A device in order to provide for the necessary swing of the pulleys 40, when'thev boom and life boat'move outwardly, I mount them in housings 46 which are pivotally hung upon pins 47 mounted in'the respective endsof the spreader 43. Similarly to the stop members or means I have provided inthe' form of the pins. 35 in the blocks36, in the construction shown in Figures 1, 4, 5 and 6,1 provide the cables 42 withstopblocks 48, in the constructionshown in Figures 7 ,8 an'dl9, which 7 stop blocks 48 are-adapted-toabut the surfaces 51 of the swinging housing members 46. In .this'i'orm ofdevice shown in Figures 7, 8 and 9, the boat support 44: is widened out,

as plainly shown, and provided with shoes adjacent each end of theboat 41 and, upon which the boatrests, when'in its'upper normal position.; f

- e5 "hold the shoulder member 39*on thelatch 28 Inboth forms ot device described, .si

7 V It will be understood that there has thus far the boom, when latch 28 is released, tends to I 11 tobear against the short rail block 12.

lVhen the boom 4 is free to rotate byreason of the release of the latch 28 from the locking lever 31, the load support 1l15 acts as a lever fulcrumed on pin 9. The weight of the lift boat 19 gives a counter-clockwise rotation to the support 14-15 about this fulcrum point 9. Since the pin 13 is mounted in both the boom .4 and the boat support 1l15, it is carried to the left, giving a counter-clockwise rotation to the boom about the pivot pin 5. This movement of the boom l in creases the distance between the pulleys and 26 until all the slack is taken out of the cable between the surface '37 and the pin by reason of this surface striking against this pin as the boom 4 rotates and moves to the left. .The armcl l of the load support is made considerably shorter than the arm 15,

so that the movement of the pivot pin 13 to the left causes the arm 15 to drop rapidly,

thus increasing the distance between the bearing surface 37 upon the under side of the top portion of the boom 4. and the support blocks 16 and 17. The cable portion 21 being of fixed length, the load is thus transferred to it.

The weightof boom tand load-support 1st15 adds to the rotating force in a counter-clockwise direction upon the upper end of the boom 4:, when latch 28 is released. The force exerted by the pin 13 upon the boom in a counter-clockwise direction acts at the starting only of the boom rotation, inasmuch as the linkage mechanism controlling the movement of load-support 14:-15 causes the load-support to drop away quickly from the under side of the life boat 19.

In order to make certain that pin 35 remains in contact with the, surface portion 37 and does not lower vertically relative to the boom 4 until the latter has completed its outward movement, the pulleys 23, 25 and 26 are so located relative to each other and to the pin 5, that the moment arm M2, Figure l, is greater than is moment arm M'1. When the cables 24 are restrained from paying out by the hoisting mechanism 52, the

-- weight of the load, after the load support 1415 has been removed, on the moment arm M-2. This 1S resisted by a force acting on arm M -l. Since arm lvI-1- isless than arm M2, the force exerted on the end of arm M l'mustbegreater than the weight of the load acting on arm M2, if the boom 4is to remain stationary. Since the cable 24 is free to move ,on the pulleys except as restrained by pin 35 bearing on the surface 37, this additional force must be applied at this point 37. Vhen the cables 2-1 are being played out, this internal force continues to hold the pin 35 and the boom surface portion 37 together, and the boom will complete its outward movement before the pin 35 and the surface portion 37 separate. Any location of the pulleys 23, 25 and 26 and pivot point 5 which will cause arm M2 to be greater than arm M-1 will satisfy these conditions. It is evident that under certain conditions the pulley 25 may not be required.

Moment arm M-2 is not constant, but is the horizontal distance between lines drawn vertically from the groove of pulley 23 and the pin 5, so that any list of the vessel will affect arm M2. A list of the vessel in counter-clockwise direction, in the assembly shown in the accompanying drawings, will increase arm M-2, and therefore, hold pin 35 more tightly against the surface 37, which action, of course, is desirable. A list of the vessel clockwise may decrease arm M2 until it is less than arm Ml. However, the assembly is such that a launching can bretiected against a back list of 30 or more inasmuch as the weight of the boat 19 im posed vertically on the support arm 15 ro tates the boom 4 in a counter-clockwise direction until arm M2 becomes greater than arm M1, after which the launching action proceeds as if there was no list of the vessel.

Inasmuch as the rotary motion of pin 9 about the pin 13 shortens the distance between the pins 7 and 9, the link 8 is provided with a slot 10 to permit this rotary movement as long as there is any possibility of the load being carried on the support arm 15, after which the link 8 prevents any excessive rotation of the support 14 15. In the broken line position shown in Figure 1, the boom 4 and the load support 1 l15 carried thereon have completed their outward movement, this movement having been stopped by the contact of the load-support end 15 with the deck 1.

In the assembly shown, two pulleys 23 and are used in. order to obtain the des red lengths of the moment arms M1 and M2. Undersuitable conditions only one such pulley would be required; whereas, there are probably conditions where even two pulleys would be required.

I In the design worked out and shown in the accompanying drawings, it is desirable more than to hinge the load-support 14-45 for three in case of alist in the ship and (3) 'so' as to cause the end 15 on the load-support arm 15 to be drawn'more closely to the pin 5 in order that said load-support and may strike the deck "1, thusacting as a stop for the boom. This stop prevents excessive r0 tation of the boom in a simple manner. The

' boom could be stopped by a chain, stop'blocks,

or other suitable mechanism, where the particular. conditions warrant. The proportions otthe design worked out and shown in the accompanying drawings require that theisupport 14L'15 move relatively to the boom, However, other proportions.would permi this supporttogbe 'se cured rigidly to the boom and still glve'the desired results and, where the conditions permit, such a. fixing of the load-support would be highly desirable. ,Otherconditions might make it desirable to pivot the load support 1415 from some fixed part of the vessel, such as the deck housing 2', possibly ,near thepivot 9'and then control its move ment by slides, links, or other mechanism, from a point at or near thepin 1'3 'on'the boom. The link 8 producesthe desired motion in the support 1-15 in the case worked out and shown and, ofcourse, such motion could be obtained by any number ofsuitable links, slides, stops,'etc.

:ltwill be noted from the accompanying drawings that thelboat 19' and the launching mechanism arehigh slung and that ami-nimum amount of deck space is utilized during the usual non-operat1ng position of the said 7 elements. The counterweight 29, of course,

' saidstop means permitting downward move-j tends to throw the'latch 28 out of locking positionand it quickly does thus" act, to move the latch 28 out of the way, when the locking memberBl is manuallylifted; This lifting of the-locking member 31 permits the-inter-v mediate starting of the outward rotationof the boom andthe dropping away of the loadsupport 1 l15 from under the life boat 19,

the pin quickly contacting with the under surface 3.7 of the top end of the boom to stop the boom movement; The action thereafter is controlled by the mechanism 52 controlling the play of thecables 24. Y i Y What I claim is v 1. A load-carryingand comprising, a main support, a boom pivoted adgacent itslower end to said support and adapted vtov move outwardly-under the force of gravity,.-a load-support pivoted to the boomfand :connectedby a link to said main support so as to-be 'capableiof movement awaytrmn the' latter, pulleys mounted on the boom, a cable; carried over said pulleys and: adapted to carry the load during launching, stop; means-fcr" limiting the 'u' ward movement of the cable relativewtothe oom',

men-tot the cable all times, means 011 controlling; the cable ;movement,' andimeans for launching device 7 carried over said pulleys and adapted to carry the load during launching, means for controlling the cable movement, and; means for-'detachably locking the boom in raised position to the main support, the construction beingsuch as to'oause said load-support to move away from the supported load during the initiallaunching movement of the boom froma normal range of positions of the main support, the loadsupport being positioned in vertical alignment with the loadcarryingposition of the cable, and the connection of said load support to said boom and main support being such that the load Q pressure on said load support, if the main support lists inwardly an amount greater than its normal range; of positions, causes the boom to 'rotateoutwardlyuntil the normalloperativeefliect'obtainsv V 3. A load-carryingiand launching device comprising, amain support,a' boom pivoted adga'cent its lower end to said support and adapted to move outwardly under the force of gravity, a 'load su'p'port pivoted to the boom and connected to; the main'support so as to be capable of movement away from the latter, spaced pulleys mounted on the boom,

a sheave mounted on said main support outside the plane passing through'said pulleys, a cable carried over said pulleys and sheave and adapted to; carry the load substantially during the entire launching movement of the boom, means for controlling the cable movement, thesheave pivotpoint and said pulleys being so located relative; to'thepivot point of said boom as to tend to cause an outward rotation of the latterwhen a load is applied 'tothe cable, and means for detachably looking the boom in raised position to the main supp-ort.-

LA load-carrying and launching device comprislng, a main support,-a boom pivoted adjacent its lower endto said support .and adapted to move outwardly underthe force of gravity, a load-support secured to said boom," saidxload-support being p1votallyse .cured-relatively'to said main support'an d' movable away fromthe latter, means for controlling" the movement of said load-support, a pulley mounted onysaidbooinadja- :cent the carryin-gend of the latter,a cable and-controlling mechanism therefor, a seeond pulley out of-line with the plane con ing, such that the tendencdy taining the axis of said first pulle and said controlling mechanism, said cab e playing over both said pulleys, the construction beof the cable is to cause the rotation of sai boom, and a stop member on said cable beyond said first-mentioned pulley and adapted to contact with said boom, said stop member limiting only upward movement of said cable relative to said boom.

5. A load-carrying and launching device comprising, a main support, a boom pivoted adjacent its lower end to said support and adapted to move outwardly under the force of gravity, a load-support pivoted intermediate its'ends to said boom, a link pivoted at one end to said main support and at the other end to said load-support, a sheave a mounted on said main support, a pulley mounted upon said boom adjacent the carry ing'end of the latter, a cable adapted to play over said pulley and said sheave, and control mechanism for the movement of said cable, a movably mounted second pulley over which said cable plays and located intermediate said firstanentioned pulley and said sheave, said second-mentioned pulley being out of line with the plane containing the axis of said first-mentioned pulley and said sheave so that the load on the cable causes the rotation of said load-support to move away from and toward said main support, the construction being such that upon the initial movement of said boom said load-support moves away from the load mounted thereon, a pulley mounted upon said boom and a sheave mounted upon said main support and a cable playing over said pulley and sheave, mechanism 'for controlling the movement of said cable,

and means for detachably locking the boom in raised position to the main support.

7. A load-carrying and launching device comprising, a main support, a boom pivoted adjacent'its lower end to said support and adapted to move outwardly under the force of gravity, a load-support pivoted intermediate its ends to said boom, a link pivoted at one end to said main support and at the other end to said load-support, an elongated slot formed in said link, said load support being provided with a roller whose axis is movable in said slot, a track section secured to saidmain support and over which said roller plays,.a pulley mounted upon said boom and a sheave mounted upon said main support, a cable playing over said pulley and sheave, mechanism for controlling the movement of said cable, and means for detachably locking the boom in raised position to the main suport. I p 8. A load-carrying and launching device comprising, a main support, a boom pivoted adjacent its lower end to said support and adapted to move outwardly under the force of gravity, a load-support pivoted intermediate its ends to said boom, means for controlling the relative motion between the boom and said load-support, the latter being formed at one end with a supporting surface adapted to form a stop for the movement of the boom when the latter has rotated outwardly a predetermined distance, a pulley,

its ends tov said boom, a link pivoted at one end to said main support and at the other end to said load-support, the latter being formed at one end with a supporting surface adapted to form a stop for the movement of the boom when the latter has rotated outwardly a predetermined distance, a pulley mounted upon said boom and a sheave mounted upon said main support, a load-carrying cable playing over said pulley and sheave, mechanism for controlling the movements of said cable, and means for detachably locking the boom in raised position to the main support.

10. A load-carrying and launching device comprising, a main support, a boom pivoted adjacent its lower end to said support and adapted to move outwardly under the force of gravity, a load-support pivoted intermediate its ends to said boom, a link pivoted at one end to said main support and at the other end to one end of said load-support, the other end of said load-support being adapted to sustain the load, a sheave mounted on said main support, a pulley mounted on said boom adjacent the carrying end of the latter, a second pulley mounted on said boom intermediate said sheave and said first-mentioned pulley and outside of the plane passing through said sheave and pulley, a cable playing over said sheave and pulleys, a stop member on said cable beyond said first-mentioned pulley and adapted to contact with said boom, said stop member being slightly out of contact with said boom when the load is rested and connected to sea on said load-support, control mechanismfor; actuating said. cable,,.and means for detachably locking thezboom in raised position. to, the main'support. V i 5' 3,11; A load-carrymg comprisinga mainsupport, a boom pivoted: near its lower end to said support and adapt ed to move outwardly-i under the force .of gravity, a load-support pivoted to said boom 'd main support, a pulley on the load-carrying end of saidboom, a cable carriedover said pulley and adapted to carry the load during launching, means fors controlling the cable movement, stop means '1 for limitingupward. movement of the load relative to said boom, said stop means permit.-

. said support member when the load bears ting downward movement of the load at all times, rand f means for locking said vboom 1n raised position, the construction being such r as to causesaid load-support to move away from the supported'load during the. initial launchingmovement of said boom. 5 Y 12. A load-carry ng and launching dBVlCG comprising-a main support member, a boom member pivoted near its lowerend to'said support member and adapted to move outwardly under the force of gravity, aloadsupport pivoted to oneof said members andbearing against the other of said-members so as to urge said boom member away from uponsaid iload-support,=a pulley on the loadcarrying end of said boom member, a cable carried over said pulley and adapted to carry the :load during launching, means for con trolling the cable movement,stop means for limiting upward movement of the load rela' tive to said boom member, said'stop means-- permitting downward'movement of the load at all times, and means for locking said boom e member in raised position, the construction being such as to cause saidload-supportto move away from the supported load-during the initial launching movement of said boom j member s 13.- A load-carrying and launching device comprismgia main support member, aboom memberpivoted near its lower end to said support member; and adapted to move out" wardly under the force of gravity, a load-' support pivoted to one of said members, a

link connecting said load-support to the otherof said members. and having a loose connection at one end, apulley on the load-car- I, rying end of said boom member,'a cable car:-

ried over said pulley and; adapted to carry the load during launching, means for controlling the cable movement, stop means-for limiting upward movement of the load relative 1 to said boommember, said stop means permittingdownward movement of the load at all times, andmeans for locking said boom member .LlIl raised position, the construction beinglsuch as to cause said load-support to j; move away from the supported load during and launching device,

" tame theinitial launching movement of said boom memb'erl l 14. A; load-carrying. and launching-device comprising a; main support, a boom pivoted near'its lower end to said support and adapt-j ed to move outwardly under the force of gravity, a bell-crankpivoted to said boom,

one leg of said bell-crank constituting sub-1 stantially the entire support for the load in its inoperative position and the other leg.

having a roller bearing against said main support, a pulley on the load-carrying end of said boom, aicable, carried over said pulley' and adapted 'to'carry the load during launching, means for oontrollingpthe cable movement, stop means for limiting. upward movement of theload I'GlfltlVBilO said boom, said stop means; permitting downward movement of the loadat all times, and means 'for looking said boom in raised position, the construction being such as to cause'said load-support to move awayfroin the supported load during the initial launching movement of said boom.

15, A load-carrying and launching device comprising a main support, a boompivoted near its lowerend to said support and adapted to move outwardly, a load-support adapt ed to support substantially the entire load in its inoperative position, a pulley mounted on the load-carrying end of said boom, a cable carriedover said pulley and adapted to carry the load during launching, means for con trolling the cable movement, means for locking said boom in raised position, and stop 7 said pulley and adapted to carry the load dur-' ing launching, and means for controlling the cable movement; a load-support comprising a -bell-crank,one leg of said bell-crank being providedwith portions conforming to the" form of the load to be supported, the'other leg being shorter than said first-mentioned leg and having a roller at lts free end for hearing against said main support, andsaidbell cranki being adapted to be pivotedtosaid boom attheangle formed by its two legs.

17. vIn a load-carrying and launchingdevice having a boom pivoted near its lower end to a main support for outward movement therefrom, said boom' having a pulley near its loadecarrying end and a cable carried over said pulley and adapted to carry the loaddur-i ing launching, and means forcontrolling the cable movement; a load-support comprising a lever pivoted between its ends to said boom, the portion of said lever to one side of the pivot being adapted to support substantially I the entire load in its ino erative osition and the remaining portion of said lever having a link secured thereto for connecting said lever to said main support, the end of said remaining portion being provided with means for rolling contact with said main support.

18. in a load-carrying and launching device having a boom pivoted near its lower end to a main s ipport for outward movement therefrom, said boom having a pulley'near load-carrying end and a cable carried over said pulls Y and adapted to carry the load during launching, and means for controlling the cable movement; locking means for said boom comprising a dog on said main support, a latch member pivoted on said boom, said latch member having a shoulder adapted to engage said dog and a counterweight adapted t urge said shoulder out of engaging relation with said dog, means for securing said latch member in locking position, and means on said main support for bearing against said boom to maintain said shoulder in close engagement with said dog when said boom is in its raised position.

19. in a load-carrying and launching device having a boom member pivoted near its lower end to a main support member for outward movement therefrom, said boom member having a pulley near its load-carrying end and a cable carried over said pulley and adaptedto carry a load during launching,

and means for controlling the cable movement; a load-support comprising a bell-crank having legs of unequal'length and being adapted to be pivoted to one of said members adj aeent the angle formed by its legs, the longer leg being adapted to support the load and the shorter leg being adapted to bear against the other member, whereby the loadsupport tends to move the boom member outwardly when the load is appliedto the longer leg, and the construction of said device being such that the load may act on said longer leg during the initial stages of the launching.

20. A load-carrying and launching device comprising a main support member, a boom member pivoted adjacent its lower end to said support member and adapted to move outwardly under the force of gravity, means for locking said boom member in its inoperative position to said support member, a loadsupport pivoted to one of said members and adapted to support a load in the inoperative position of said boom member, spaced pulleys on said boom member, a cable-guiding means mounted on said main support member below the plane passing through the axes of said pulleys when said boom member is in its raised position, a cable connected to the load and carried over said pulleys and said guiding means, and means for controlling the movement of said cable, said load-support being movable away from the load and the load being applied to said cable during the initial stages of the launching whereby said cable tends to cause outward movement of said boom member.

21. A load-carrying and launching device comprising amain support, a boom pivoted adjacent its lower end to said support and adapted to move outwardly under the force of gravity, a load-support secured to said boom, said load-support being adapted to support a load when the boom is in its inoperative position and being movable away from the load during the initial launching move ment of said boom, a pulley mounted on said boom adjacent its load-carrying end, a cable, mechanism for controlling the movement of said cable and having a cable-guiding means, a second pulley on said boom out of line of and above the plane containing the axis of said first pulley and passing through said guiding means, said cable playing over both said pulleys and said guiding means whereby said cable tends to cause out-ward movement of said boom when the load is applied to said cable, and a stop member on said cable between the load and said first-mentioned pulley.

Signed by me this 20th day of December,

ANGUS D. MoKENZIE.

CERTIFICATE OF CORRECTION.

Patent No. 1,827,534. Granted October 13, 1931, to

ANGUS D. McKENZIE.

It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows: Page 2, line 14, for "in" read is; page 3, line 18, for "lift" read life; page 4, line 4, for "and" read end, and lines 41 and 42, for "intermediate" read immediate; page 6, line 104, claim 15, for "being" read urges; and that the said Letters Patent should be read with these corrections therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 17th day of November, A. D. 1931.

M. J. Moore, (Seal) Acting Commissioner of Patents. 

